Electrode holding and positioning

ABSTRACT

A consumable electrode is positioned in a furnace under utilization of radially outwardly projecting ribs, at least one wheel with projection engages one of the longitudinal ribs and provides a deformation thereof in terms of indentation and thereby is and remains briefly in engagement with the rib such that the wheel with and through its projection holds and advances that electrode. The wheel has prongs, serrations or teeth and preferably cooperates with a counterwheel on the other side of the rib.

BACKGROUND OF THE INVENTION

The present application relates to a method and device for positioningof a self-baking filler electrode in electrical reduction and arcfurnaces, particularly under utilization of electrodes having a jacketwith radially outwardly extending longitudinal ribs or fins provided forengagement with positioning structure.

Electrothermic smelting and melting furnaces particularly electricallyoperated reduction furnaces with or without arc type heating usuallyemploy self baking filler electrodes of the so called Soederberg type.These filling electrodes are comprised of a thin, shaping sheet metaljacket filled with the consumable material. These electrodes are verysensitive against radial impacts, pressures or the like as they mayoccur; "radial" of course to be understood in relation to the axis ofthe electrode. Upon installing such electrodes they require usually adevice for placing the electrode tip or end into a particularelevational position which is to be maintained and necessary oradvantageous for metallurgical procedure. Repositioning the electrode isa continuous operation in order to offset the dimensional variations asthe electrode is consumed.

German Pat. No. 83 14 30 discloses such an electrode feeding structurewith a gear transmission of the rack and pinion drive variety.Projections, generally speaking, are movable parallel to the axis of theelectrode and engage indents in the electrode jacket. The indents couldactually be provided for during operation and synchronously with thefeeding operation and by means of a structure which is separated fromthe electrode feeding device.

On holding as well as during feeding of the electrodes radial forceswill therefore be exerted on the jacket. These are necessary in order toprevent uncontrolled slide through of the electrode. Controlling theseforces and the radial forces for providing the indents is actually quitedifficult. Swiss Pat. No. 323760 discloses a similar electrode feedingdevice of this type which requires a prefabricated groove in theelectrode to receive a rack to be moved by a pinion.

German Pat. No. 33 04 099 discloses structure wherein a clamping deviceengages radially the jacket and here outwardly extending longitudinalribs. This electrode drive device is disadvantaged by the fact that theyare technically of rather complicated construction for moving theelectrode one needs twice as many clamping structures. The duplicationin number is required since only half of the clamping brackets willengage the ribs for a certain period of time and the have to be releasedand returned to re-engage the structure. During that period of coursethe electrode is not permitted to slide and that is the reason a secondset of clamping brackets is needed.

In addition the clamping elements have to be pressure biased foremergency cases for example in case of an electric current failure, apressure drop or the like; the electrodes must be held firmly and mustnot be permitted to move in an uncontrolled fashion. The emergencyarrangement includes spring operated clamping brackets which means thathigher release pressure is required for disengagement to overcome thespring bias.

DESCRIPTION OF THE INVENTION

It is an object of the present invention to provide a simple reliablenew and improved method and equipment for stepless i.e. continuouslyadvancing electrodes of the type mentioned above and which shows littleexpenditure and operates with a simple, constructed positioningstructure in order to obtain the desired goal.

In accordance with the preferred embodiment of the present invention, itis suggested that the positining device itself deforms the abovementioned longitudinal ribs particularly as the electrode is loweredsuch that on vertical movement of the electrode definite engagementobtains between the positioning device and the deformed longitudinalribs as they are being deformed and in a form and shape matchingrelationship. The ribs are preferably provided by the positioning devicewith cuplike indents or with a wavy or sawtooth corrugating pattern. Thepositioning device itself is preferably provided with wheellikeelements, one wheel at least being of a configuration that provides theabove mentioned shaping and is being driven for vertically moving theelectrodes. Hence it can be seen that through positive contour matchingengagement the electrodes are positioned and movable for continuousdisplacement in up and/or down directions thus permitting lowering aswell as lifting.

In a typical case one may use three positioning devices of this kindcooperating with three grooves and being provided in the same level.This then permits an exact fixing and establishing of the position ofthe electrode tip. Hence not only is axial centering provided but theelectrode tip is exactly controlled with regards to its position. Theelectrode will be adjusted corresponding to the electrical andmetallurgical requirements, not just in a particular level but inparticular relation to the molten material. This obtains in addition toaxially positioning the electrodes to be precisely in the center of thefurnace which is also a vertical axis.

For deforming the longitudinal ribs in the electrode one needs at leastone shaping wheellike element. This wheellike element is preferablyconstructed similarly to a gear. The counterwheel may also be providedas a gear or it may be deformable so that the longitudinal ribs are justdeformed by the teeth of the principal drive wheel. In anotherconfiguration as stated the wheel is provided with thornlike peaks andextensions which configuration is of advantage as the deforming work tobe exerted upon the longitudinal ribs is very low. In addition an exactpositioning and holding of the electrode is indeed provided through thepeaks which engage potlike or cuplike indents of the longitudinal rib.In this example the counterwheel should have bores which permits thepeaks of the other wheel to push sheet material into these bores.

All positioning wheels are preferably driven. The wheellike elements ofthe positioning device permit easy adaptation towards an emergencyequipment. The emergency equipment may include a locking element such asa plunger for engaging one of the wheels and stopping it. This wheelthen holds the electrode. These elements may either be operatedcontinuously e.g. during lowering of the electrode or only in the caseof energy dropout. On the other hand the plunger may be used, inaddition, and during operation to constitute a break. In all of thesecases it can be seen that the emergency holding equipment is simple andeffective. Further included in the safety equipment is the measuringtransducer arranged at the electrode in which response to the loweringspeed of the electrodes. Should that speed exceed a predetermined limitthen the emergency equipment may be triggered.

DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter which is regarded as theinvention, it is believed that the invention, the objects and featuresof the invention and further objects, features and advantages thereofwill be better understood from the following description taken inconnection with the accompanying drawings in which:

FIG. 1 illustrates a cross sectional view through a furnace with anelectrode positioning device improved in accordance with the preferredembodiment of the present invention for practicing the best modethereof;

FIG. 2 is the top view of positioning device used in FIG. 1;

FIG. 3 is an illustration of a drive wheel being part of the positioningdevice and having pointlike projections or thorns;

FIG. 4 illustrates somewhat schematically a perspective view of alongitudinal rib for electrode deformed by structure shown in FIG. 3;

FIG. 5 is a view similar to FIG. 3 but shows deformation throughgearlike wheels; and

FIG. 6 is also a view similar to FIG. 3 but shows a sawtooth wheel.

Proceeding now to the detailed description of the drawings, FIG. 1illustrates a furnace 10 for smelting or melting into which projects anelectrode 20. The electrode includes a jacket 21 with two (or more) ribs22 projecting in radial direction. Reference numeral 25 refers to thefiller material which is the basically consumable item for the selfbaking electrode. Reference numeral 30 generally refers to one of thepositioning devices and 30' is the second one. In this case the devices30 and 30' are disposed diametrically in relation to each other andacross the axis 26 of the electrode which is also the axis of thefurnace 10. The positioning structures 30 and 30' are connectedrespectively to controllers 50 and 50' which include pickup transducers51 and 51' monitoring the passage of the electrode 10 in up or downdirection while transducers 52 and 52' establish the distance of theelectrodes from the respective instrument and, thereby, monitor thehorizontal position, meaning that these devices 52 and 52' monitor anydeviation in electrode position from coaxial one as far as the furnaceaxis 26 is concerned.

As far as FIG. 2 is concerned, but also in FIG. 1 the two positioningdevices are shown to be of different construction. In reality one willof course use one and the same kind of positioning devices for all ribsbut for purposes of illustrating different kinds have been illustrated,meaning that FIGS. 1 and 2 can also be understood to show differentembodiments to the left and to the right of what is in effect a verticalplane.

The right hand positioning device 30 is driven by a motor 32. Thispositioning device includes a first drive wheel 31 and a counterwheel33. Both of them are driven. In other words, 30 includes a branchingtransmission coupling both wheels 31 and 33 to motor 32. These twowheels 31, 33 are in fact gears. Their engagement is shown particularlyin FIG. 5. The two gears 31 and 33 are positioned in relation to eachother just as gears are with the teeth in one wheel projecting intoindentations of the other wheel. In this case now the longitudinal rib22 is interposed and it can be seen specifically that at first in FIG. 5the rib 22 is smooth and straight but on engagement with the gears 31and 33 corrugations 24 are impressed into the rib resulting in acorrugation pattern. This pattern in turn permits the two wheels 31 and33 to grip firmly and without slippage into the rib 21.

As shown also in the right hand portion of FIG. 5 an emergency structure40 is provided which includes a pin plunger or bolt 41. In the case ofpower failure or the like pin or plunger 41 will be pushed into theclosest groove or indent of the gear 33; that is actually a positionshown in FIG. 5. Pushing may be carried out for example by means ofspring bias or the like. This plunger 41 is of course retracted e.g.upon normal elective current flow, while the spring force will propelplunger 41 forward and thereby stopping the wheel 33 which in turn willcorrespondingly hold wheel 31 with the rib 22 with indents 24interposed. The motor 32 e.g. either has dropped out because of powerfailure or is separately turn-off or will just stall. In any event insuch an emergency situation the drive wheels 31 and 33 will hold the riband the electrode and prevent slipping through.

The positioning device 30' on the left hand side of the FIG. 1 and FIG.2 shows another version for positioning which includes a wheel 34 (seealso FIG. 3) which has along its periphery thornlike projections, pointsor the like 34a. This wheel cooperates with a counterwheel 35 havingpotlike indentations or recesses 35a. In this case the longitudinal rib22 of electrode jacket 21 is deformed by the wheel 34 in that theprongs, points, thorns or the like 34a each push an indent into the ribon each contact. The pockets 35a are disposed on the other side toreceive the pushed in material of the rib 22.

As a consequence of the arrangement and construction shown in FIG. 3 and4 potlike indents 23 are produced which of course are and remain forcertain short period of time an engagement with the two wheels 34 and35. As a consequence also here positive engagement between this drivemechanism and the originally smooth rib 22 obtains.

In addition one can see from FIG. 3 that there is also a plunger 41which in this case selectively engage when propelled forward one of theindents 35 to thereby prevent further rotation of the two wheels.

FIG. 6 shows the rib 21 being deformed by a wheel 36 with a sawtooth 36aperiphery. The wheel 37 on the other side has a highly ductile oryielding surface.

The invention is not limited to the embodiments described above but allchanges and modifications thereof, not constituting departures from thespirit and scope of the invention, are intended to be included.

We claim:
 1. Apparatus for positioning a consumable electrode in afurnace, the electrode having a jacket with at least two radiallyoutwardly projecting longitudinal ribs, a positioning devicecomprising:at least one wheel with projections engaging one of thelongitudinal ribs and providing a deformation thereof in terms ofindentation which thereby is and remains briefly in engagement with saidwheel such that the wheel with and through its projection holds andadvances that electrode.
 2. Apparatus as in claim 1 there being acounter wheel cooperating with said wheel having the projections. 3.Apparatus as in claim 2 said wheel having thornlike projections, saidcounterwheel having peripheral bores.
 4. Apparatus as in claim 2 saidwheel and counterwheel both being of gear configuration to providecorrugationlike deformations.
 5. Apparatus as in claim 2 said wheelhaving a sawtooth contour as projections, said counterwheel having asmooth surface made of a ductile material.
 6. Apparatus as in claim 2including an emergency equipment for selective engagement of an indentin said counterwheel.
 7. Apparatus as in claim 6, the emergencyequipment including a plunger to provide for such selective engagement.8. Apparatus as in claim 1 including means for tracking progress of saidelectrode to control progression thereof.
 9. Apparatus as in claim 1wherein the engagement provides for regularly spaced deformations. 10.Apparatus as in claim 1 including means for tracking position of saidelectrode to control its progression.
 11. Apparatus for positioning aconsumable electrode in a furnace, the electrode having a jacket with atleast two radially outwardly projecting longitudinal ribs, a positioningdevice comprising:two wheels each with projections engaging thelongitudinal ribs and providing deformations thereof in terms ofindentations which thereby are and remain briefly in engagement withsaid wheels such that the wheels with and through its projection holdsand advances that electrode; and counter wheels respectively cooperatingwith said wheels having the projections.
 12. Apparatus as in claim 11said wheels having thornlike projections, said counterwheel havingperipheral bores.
 13. Apparatus as in claim 11 said wheels andcounterwheel both being of gear configuration to provide corrugationlikedeformations.
 14. Apparatus as in claim 11 said wheels having a sawtoothcontour as projections, said counterwheel having a smooth surface madeof a ductile material.